We’ll be sitting down to turkey dinners this Thursday, watching endless college football games, and trying to ﬁgure out what to do with all the leftovers.

Thanksgiving Day did not become a national holiday until Oct. 3, 1863, when President Abraham Lincoln established the last Thursday of November as the ofﬁcial national day of thanks. In 1939, an effort to help the retail industry moved Franklin D. Roosevelt to change Thanksgiving Day to the third Thursday of the month, but in 1941, Congress put the day mostly back where Lincoln wanted it, by moving it to the fourth Thursday of November. That meant that in some years, there is an extra, fifth Thursday that makes the retail folks happy, and maybe Lincoln’s ghost, too. And there it has stayed ever since.

John Smith didn’t have anything to do with Thanksgiving; his gig was down in Jamestown. But it is a neat story.

Ask a dozen people and you’ll get a dozen answers about why we celebrate Thanksgiving. Most suspect it has something to do with Pilgrims dressed in black and wearing flat-topped witches’ hats, except the Pilgrim women who wore hats that looked a lot like the one Whistler’s mother was wearing in that famous painting a couple hundred years later. And there was something somewhere about thanking God; or was it the Indians? And weren’t Capt. John Smith and Pocahontas involved somehow?

Good guesses they are, too. Not right, but good (Capt. Smith and his girlfriend were doing their thing down in Virginia).

In 1620, 137 English men and women stepped ashore at what is now Plymouth, Mass. and established Plymouth Plantation. Of the passengers on the Mayﬂower, 35 were members of the English Separatist Church–Puritans–who had come to the New World via Leiden, Holland. The separatists itched to leave Holland as much as they had itched to leave England. The Church of England was altogether too Popish and the Hollanders were scandalously tolerant of all kinds of religious zealots–like the separatists for instance—and that just wouldn’t do.

The Puritan story goes back to the reign of England’s Henry VIII, who split England’s church from Rome. Henry’s daughter, Mary Tudor–known to history as Bloody Mary–assumed the throne in 1553. She set about returning the kingdom to the Catholic fold mostly by burning numerous Protestants at the stake, and forcing thousands more into exile. When Mary died, her younger sister, Elizabeth, was crowned queen. She set a new Protestant course, persuading the exiles to return.

While overseas, though, the exiles had been excited by the militant Protestantism sweeping out of Geneva, Switzerland, and they looked upon Elizabeth as the savior of the non-Catholic church. Unfortunately, celebrated Protestant theologian John Knox (with the fires from Mary’s Protestant elimination program barely extinguished) had attacked the right of women to rule, which did not endear the militant religionists to the queen. Elizabeth suggested the zealots were “overbold with God Almighty, making too many subtle scannings of his blessed will, as lawyers do with human testaments” (lawyer bashing in the 16th Century!).

Thus was the separatist movement born, with its members dubbed Puritans because of their certainty theirs was the only pure way to salvation.

Gradually, the separatists became more radical in their demands on the Church of England. When the church refused to change, many separatists physically separated, heading first to Holland and then to the New World.

Saints and Strangers alike signed the Mayflower Compact, which worked pretty well until the Puritans gained an unambiguous majority, at which time they decided that live and let live tolerance thing was for losers.

When they arrived on the shores of the New World in 1620, the Puritans were in the minority. A year later, Saints (what the Puritans called themselves) and Strangers (everybody else) alike joined in that ﬁrst Thanksgiving, thanking God they were still alive and thanking the Indians for helping them stay that way.

Although many had died of disease and cold, the Strangers probably looked back on 1621 as the Good Old Days a few years later. The number of Puritans increased rapidly as more immigrated from England. Soon they had enough political power to make Puritanism the sole state religion in Massachusetts and to bar non-Puritans from all political activity. Persecuted in England for their religious views, the Puritans moved to the New World to freely persecute others, which they did with gusto.

Strangely enough, all the Protestant zealots who came to the New World were not monolithic Puritans. The diversity of religious zeal among new arrivals and the upheaval of the English Civil War (fought for politico- religious reasons; it all started with a forced change in liturgy for the Scots) resulted in too many heretics to deal with. After a few decades of whipping, banishment, dunking and the like, the sheer number and ardor of those holding divergent views resulted in more tolerance than the separatists wanted.

Partly thanks to the zealotry of the Pilgrims, as well as extreme religious friction in Europe, a century and a half after the Pilgrims arrived their descendants insisted that religious liberty be enshrined in law as the price of approving the newly written U.S. Constitution.

Religious zealotry caused a reassessment of many issues, and pointed out the need for checks and balances in government. Warned 17th Century Puritan theologian John Cotton: “Let all the world learn to give mortal man no greater power than they are content they shall use, for use it they will…It is necessary that all power that is on earth be limited, church power or other…It is counted a matter of danger to the state to limit prerogatives, but it is a further danger not to have them limited.”

Ironically, the Pilgrims’ religious tyranny led their own descendants to insist on adding a Bill of Rights to our Constitution, including the First Amendment, prohibiting the very kind of state religion the Pilgrims came here to establish. And maybe that’s what we ought to be honoring this Thursday: The freedom we enjoy to celebrate God’s grace however we wish, or to ignore the whole thing and watch football.